Consistent Use of Monthly Vaginal Ring Protects Against HIV

TUESDAY, July 19, 2016 (HealthDay News) — When used regularly, a monthly vaginal ring medicated with the antiretroviral drug dapivirine may be an effective way for women in sub-Saharan Africa to protect themselves from HIV infection, according to research presented at the 21st International AIDS Conference, held from July 18 to 22 in Durban, South Africa.

This phase III trial, known as the ASPIRE study, involved 2,629 African women between the ages of 18 and 45. Researchers divided the women from Malawi, South Africa, Uganda, and Zimbabwe into two groups. One group was assigned to use the dapivirine ring and the other group to use a placebo ring that contained no medication.

Between August 2012 and June 2015, 27 percent fewer women in the dapivirine ring group were infected with HIV than in the placebo group. The researchers determined how consistently the women used the ring by testing levels of dapivirine in their blood every three months, and by testing the amount of residual drug remaining in used rings that women returned to the clinic at monthly visits. The researchers classified the women based on how regularly they used the ring, ranging from non-use to almost perfect use. They found that women who appeared to use the ring most regularly from month to month could cut their HIV risk by more than 50 percent and, in some cases, by 75 percent or more.

“Adherence to HIV prevention strategies is not always perfect, and we knew that not all women used the ring consistently, so we developed an analysis to explore the degree of HIV protection that was associated with more consistent use,” principal investigator Elizabeth Brown, Sc.D., a research professor at the Fred Hutchinson Cancer Research Center and the University of Washington in Seattle, said in a news release from the Microbicide Trials Network. “Across all analyses we saw high adherence was associated with significantly better HIV protection.”